Earlier, he missed a conversion from a relatively handy angle which also would have won the game, although it was his run and pass which put wing Buxton Popoali'i over for the try.
Referee Mike Fraser will also be in the spotlight for failing to penalise Hawkes Bay prop Ben Franks for attempting to kill the ball in a ruck when right in front of his own posts as the minutes ticked down.
The ruckus will mean little to the Magpies, though, who face Counties Manukau in their first defence at McLean Park on Saturday.
"I'm just so happy I really don't know what to say,'' said captain Mike Coman. ``Thanks to all you supporters who came all the way from Hawkes Bay. I'm just so proud for the province, they been waiting for it, they've been desperate for this occasion.''
Hawkes Bay, who were disappointing in losing their grudge match to Bay of Plenty in Tauranga last week, began nervously, but soon took control through their big men, especially No8 Mark Atkins and lock Mark Abbott, which allowed halfback Alby Mathewson and first-five Ihaia West to work their magic. It was West's individual try halfway through the second half which pushed the score out to 20-9 and virtually shut the door on the home side.
"It's an amazing feeling, it hasn't quite sunk in yet,'' said West. ``You couldn't hear anything with the crowd... The boys just managed to pull through and I'm stoked we could do it.
"At halftime we felt we were playing all the rugby but we weren't that far ahead on the scoreboard. We just wanted to keep playing territory and put pressure on them.
"With that crowd getting behind them in the last 10 minutes, man she was nervous.''
Centre Richard Buckman also shone for Hawkes Bay. It was his run around Tom Donnelly and offload to Gillies Kaka which led directly to Telusa Veainu's try in the first half and the visitors took that confidence and momentum on to the field after the break.
The sight of All Blacks prop Franks taking to the pitch for the start of the second half for his Hawkes Bay debut suggested things wouldn't be getting any easier for Otago, and so it proved. West's incredible individual try, which the 21-year-old converted, was the killer punch.
Otago gave themselves a chance of overhauling the big deficit when centre Jayden Spence capitalised on No8 Paul Grant's big break but Parker's missed conversion made the task that much harder. At 20-14 it was Hawkes Bay's match to lose, and incredibly, they almost did.
Buxton Popoali'i's jinking run put Otago on the attack with nine minutes left _ the wing winning a penalty which Otago elected to kick for touch rather than goal but it proved a good decision when Parker's run put him in for a try.
"We tried our best, it wasn't quite enough today. Well done to Hawkes Bay,'' said Otago captain Grant.
Hawkes Bay 20 (Telusa Veainu, Ihaia West tries; Ihaia West 2 pens, 2 cons).
Otago 19 (Jayden Spence, Buxton Popoali'i tries; Hayden Parker 3 pens)
HT: 13-9
Hero: Ihaia West again showed he has a promising future when running the show for Hawkes Bay. He kicked four from five and scored a brilliant individual try.
Villain: Poor Hayden Parker. Billed as the guy who can kick anything from anywhere, he missed both conversions and then had his drop goal charged down in the final seconds.
